the difference in oil levels is 0.850 m
Explanation:
given data
specific gravity ρ = 0.72
pressure across P = 6 kPa = 6000 Pa
solution
we get here difference in oil levels h is
P = ρ × g × h .................1
here ρ = 0.72 × 1000 = 720 kg/m³
and g is 9.8
put here value in equation 1 and we get h
6000 = 720 × 9.8 × h
h =
h = 0.850 m
so the difference in oil levels is 0.850 m
4 days to complete the work.
Explanation:
6 MEN OR 8 WOMEN
means that each man completes the 1/(6*12) of the work per day
OR each women completes 1/(8*12) of the work per day
9 MEN AND 12 WOMEN completes …..
9 * 1/(6*12) + 12* 1/(8*12) of the work per day.
Note that we add these 2 fractions because of the word ‘AND’ .
that gives us a simple fraction of 1/4 of the work per day.
Thus reversing it, gives you time taken = 4 days to complete the work.